Multicolor cinematograph and other films



April 1, 1930. J. E. THORNTON MULTICOLOR CINEMATOGRAPH AND OTHER FILM Filed May 5. 1924 mum-Una:

unmmum ukmm summm Ill/III! uuuummm Patented Apr. 1, 1930 UNITED STATES PATENT OFFICE JOHN EDWARD THORNTON, OF LONDON, ENGLAND, ASSIGNOR TO JOHN OWDEN OBRIEN, E MANCHESTER, ENGLAND MULTIC OLOR CINEMATOGRAPI-I AND OTHER FILMS Application filed May 5, 1924, Serial No. 711,255, and in Great Britain May 18, 1923.

This invention relates to the production of transparent multi-color cinematograph filmpositives with four compartment-images formed in four colors, or in three colors with one of the colors repeated in two images.

In my application Serial No. 711,251, filed May 5, 1924, I have described a cinematograph film-positive built up of thin strips of film material produced from four component images by printing two components in different colors superimposed on one thin strip of film-material and the other two components superimposed upon a second thin strip of 1 na terial (the second pair of components being either of the same color or two different colors) and finally uniting the two printed colored strips together to form a complete multlcolor cinematograph film-positive.

This invention consists in such a film produced upon two strips of film-material sensitized on both sides, the colored images being of the graduated full-tone (non-mosaic) variety, one component image printed in a different color on each side of the two thin strips of celluloid, and the two thin films having two component images upon each, the two films being subsequently cemented together so as to assemble the four component images superimposed within the space of one picture area, thus producing pictures of four or three colors of which one component image is located on the front of the film, one upon the back, and two between the thin film supports.

A convenient division of colors for fourcolor pictures is to form red on one side and green on the other side of one thin film and blue on one side and yellow on the other side of the other thin film, but any other desired arrangement or combination of the colors may be employed, for example, a three-color picture can be produced from the four images by making two of them in the same color.

The sensitized film-material is preferably manufactured with a transparent central base of celluloid (or similar waterproof material) of only about-.OOlOO inch thick. coated upon each side with a very thin combined adhesive-substratum and light-obstructing dyed 50 layer of about .00005 inch thick, and then again coated upon each side with a sensitized colloid layer of about. .00090 inch thick. This colloid layer may be sensitized either with bichromate or silver salts, with which are mixed dyes or coloring matter to yield colored prints directly upon development; or it can be without any coloring matter, in order that the images may be dyed after development.

The two films may be of single width printed and developed as separate strips, but I prefer to make them of double-width, so that all the four section-images can be print- "ed, developed, and dried simultaneously to secure uniform density results in all images and also to ensure uniform expansion and con traction. When the double width print is finished and dried it is slit into two separate strips.

Or the whole of the sensitized colloid upon one or both sides of the celluloid base may be dyed yellow or other suitable color, the printing light pentrating the sensitized layer through this dye only deeply enough to make one print and not deeply enough to reach and affect the sensitized layer upon the op posite side. The dye used of light-obstructing arrangement is of a loose and soluble character and is washed out of the film during the various developing, fixing and washing operations, leaving a clear transparency.

Where a three-color print is desired the film is produced in similar manner, either by omitting one of the color-sections so that there are only three prints, or by duplicating one of the colors (such as the yellow for example) upon both films, so that there are still four prints but only three different colors. For three-color pictures the most convenient combination of colors consists of red, blue, and yellow.

ccuracy of registration is obtained by perforating both sections of the sensitized film simultaneously when laid face-to-face, with the same punching machine, before printing. And for ease in identification the two positivefilms and corresponding negative-films may be provided with numbers or other suitable markings which are duplicated for the same for either variety 7 same side of the film,

image-sections of every picture'of the series I of both films.

In the above description it is assumed that the positives are obtained by first making four original negatives from which prints are produced in superimposed form.

But if desired the negatives can be reduced to two if made of the screen-type in which the images are formed as alternating lines, dots, or other pattern, two colors being thus represented by each negative. These negatives can be so manipulated in printing, by interposing suitable color-filters at suitable. stages of the operations, that one of the positive images will be formed in similar lines, dots, or other pattern upon the front side of the sensitized positive film and the other image upon the backside of the film, and both so disposed that the lines of one image fall in the blank spaces between the lines of the other image, the two prints upon opposite sides of the film therefore both being made by exposing from only one negative from the for which purpose the light-obstructing dye is omitted from the adhesive substratum-layer. The positive print will therefore consist (when examined by transmitted light) of intermixed colors in alternating lines or other pattern of halftone, instead of as superimposed full-tone images.

A multi-color cinematograph positive-film built up as described therefore comprises five separate and distinct layers in each of the two section-films; and when the two are assembled and cemented together and formed into one single strip of film containing the multicolor positive pictures, it then comprises twelve layers, arranged in the following order Sectional-filo? A 1. Colloid layer contaning red print;

2. Combined substratum and light-obstructing layer;

3. Transparent celluloid base layer;

4. Combined substratum and light-obstructing layer;

5. Colloid layer containing green print; 6. Cement layer applied to face 5.

Section-film B 7. Cement layer applied to face 8;

' 8. Colloid layer containing yellow print;

9. Combined substratum and light-obstructing layer; I

10. Transparent celluloid base layer;

11. Combined substratum and light-obstructing layer 12. Colloid layer containing blue print.

In the accompanying drawings Figure 1 isan enlarged view of a fragmentary and separated piece of film constructed according to and embodying the present invention;

remaining film 13 Figure 2 is a plan view of one layer of the present film;

Figure 3 is a similarview of the second layer; and Figure 4 is a plan view of the entire film showing one complete image.

Referring to the drawings, and particularly to Figures 2, 3 and 4:, the four-color portions (1, b, c and d of the image 10 are shown as so positioned that the portions a and b are carried by one half the film 11, one upon each sensitized face or side thereof, while the portions 0 and dare carried by the with one portion 0 upon the side opposite to the portion d, so that when the cemented faces 6 and 7 of the films 11' and 13 engage, the image will be formed as shown in Fwure 4.

The two films are joined together by adhering their cemented faces 6 and 7 and then become one homogeneous film-print of four colors. For prints of only three colors, the coloring-of layers 1, 5, 8 and 12 are modified as alreadyrdescribed.

The two films having,'before printing, been simultaneously perforated with identical perforations are, by means of registration pins that exactly'fill the perforations, easily registered when assembling and cementing, so that the section images exactly coincide, and the perforations also, as if they had been punched in the completed film.

Thus the film structure set forth herein is formed of two films, similar to those set forth in my U. S. Letters Patent No. 1,250,713, cementedtogether; that is to say, two of the old two-color duplex films now upon the market are cemented together to form a fourcolor film. This result is attained by using two supports, each having only one image and one layer on each side, instead of using one support with two images and two layers on each side, as set forth in my U. S. Letters Patent No. 1,250,713 above referred .to. Although described above as applied to a cinematograph film the invention is also applicable to the production of other multicolor positive films or transparencies.

What I claim as my invention and desire to protect by Letters Patent is 1. A multi-color picture-positive having four component images in two half pictures and comprising two thin transparent supports of half thickness, one support bearing a half picture containing two component images, an image in one color upon each side of said support, and the other support bearing a half picture containing two component images, an image in onecolor upon each side of the other thin support, the two transparent supports being superimposed with the two half pictures assembled and disposed within one picture area and cemented together.

2. A multi-color film positive comprising two thin supports each of half thickness, one

of said supports bearing two component picture images in different colors, one image on one side and one image on the other side thereof, the other of said supports bearing two component picture images in diflerent colors, one image on one side and one image on the other side thereof, the two thin supports being superimposed with the four component picture-images assembled and disposed with in one picture-area and cemented together, the one picture side of one to the picture side of the other.

3. A multi-color perforated cinematograph film-positive as in claim 1, wherein the colored images are all of the graduated fulltone, non-mosaic, photographic variety pro-i duced from sensitized-material.

4. The method of producing a multi-color perforated cinematograph film-positive, consisting in forming registering perforations in two films of about halfthe standard thickness, applying a sensitive colloid to both surfaces of each and light-obstructing medium between, printing a series of red-section images upon one side and green-section images upon the other side of one thin film; printing a series of yellow-section images upon one side and blue-section images upon the other side of the other thin film; developing, and finishing the images and removing the light-obstructing medium, applying a layer of cement to one face of each film; correctly assembling and registering the two films by registering pins which exactly fit the holes, applying pressure until the cemented face of one film becomes indissolubly united to the cemented face of the other film; said films forming, when complete, a single strip of film consisting of six layers and hav ing a series of four images thereon, two being enclosed within the film, the third one upon the outer front face and the fourth one upon the outer back face of the completed multicolor film.

5. A multi-color positive film of six layers comprising two supports of cellulose, four sensitized and printed layers, two to each support, and all cemented together with two printed layers inside and two printed layers upon the outside.

In testimony whereof I have hereunto set my hand.

JOHN EDWARD THORNTON. 

